This did happen to me, and I ended up having Colonoscopy, only to find out that I have either IBS or some other problems.

I think you are dead on in saying that when smoking you are more aware or more in-tune with your body.

Sometimes I am so in-tune I feel I will be stuck there.

(Weird I know, but lately I have been feeling odd when I smoke, maybe it's the crappy street crap I have had lately, the good stuff is hard to come by around here)